Analysis of information sources in references of the Wikipedia article "Quanrong" in English language version.
There is research on the ethnic image of the northern nomadic people of the Altaic language family. It may be that this is the image of the Xianyun tribe that once posed a serious military threat to the northern border of the Zhou Dynasty. They were called "Ghost people" (Guifang) because they looked different from the Chinese. 有考证系阿尔泰语系的北方游牧民族人种形象。可能是曾经对周朝北方边境构成严重军事威胁的猃狁部族，因相貌异于华夏，被称作"鬼方"。
